Hardware RAID Support (was RE: One Last Plea For Vinum Assistance)

Sandy Rutherford sandy at krvarr.bc.ca
Thu Jan 20 05:22:40 PST 2005

>>>>> On Wed, 19 Jan 2005 22:57:21 -0800, 
>>>>> "Ted Mittelstaedt" <tedm at toybox.placo.com> said:

 >   This did teach me a lesson that I kind of knew already but
 > didn't think too much about.  That is, a software array is no substitute
 > for a hardware array.  ...

Agreed completely, which leads me to my question.

Does anybody know what the plans are for the SCSI hardware raid
controllers vis a vis CAM?  I have a Mylex Extreme RAID 1100, which
uses the mlx(4) driver.  The mlx(4) driver does not use CAM, whereas
its cousin the mly(4) driver does interact with CAM.  

I corresponded with Michael Smith, the principal author of both
drivers, a while ago and he told me that it was a pain in the neck to
integrate mly(4) with CAM and he did not forsee this ever being done
for mlx(2).  One side-effect of this is that although the RAID setup
utility for the card does allow a channel(s) to be designated a plain
non-RAID SCSI channel for use by a tape drive or CDROM, the FreeBSD
driver does not support this.  Also, the mlxcontrol(8) facility is a
little on the basic side, with most of the capabilities of the card
not supported.

My main point is that support for SCSI hardware RAID seems to be a bit
of a dog's breakfast at the moment and are there plans to brings
things together?


1. Please do not ask me to donate a card to the developers.  I don't have a
   spare.  However, I know how the game is played and I am not asking
   anybody to donate their time to my problems.  My only serious
   problem was a bug in mlxcontrol, for which I submitted a PR, with a

2. If anybody is looking for a hardware RAID card, I can recommend the
   Extreme RAID 1100.  It's a triple channel U2W card.  I got mine for
   a song on Ebay.  Note that it is definitely worth the trouble to
   update to the latest version of the firmware.


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